Propulsion means for naval torpedoes



June 20, 1944. D. G. FAwKEs PROPULSION MEANS FOR'NAVAL TORPEDOES Filed Jan, 4, 1943 WW ww JRNU NNN

YES

Patented June 20, 1944 PROPULSION MEANS FOB, NAVAL TORPEDOES Donald G. Fawkes, Chicago, Ill.

Application January 4, 1943, Serial No. 471,309

3 Claims.

cases a target ship has been successfully maneuvered to avoid a torpedo after itswake has been sighted, while such maneuvering would have been unsuccessful if the torpedoes had been driven by the high speed reaction motor disclosed herein.

The conventional propeller-driven type of torpedo now in general use is limited to the presently attained speeds for, in the first place, the propeller diameter cannot be increased beyond the diameter of the torpedo tube, and, in the second place, the rotational speed of the propeller cannot be increased without greatly reducing the efficiency so that a larger, and therefore a wastefully more powerful motor would be required.

Accordingly, an important object of my invention has been to provide a torpedo having much higher speeds than present torpedoes but without making it necessary to increase the size of the torpedo or the torpedo tube. To achieve these desirably higher speeds, I have substituted a reaction propulsion motor (of a type to be described hereinafter) for the propeller drive commonlyy employed.

Itis my object to provide a reaction motor consisting of a combustion chamber in the stern of the torpedo, into which compressed or liquefied oxygen o r air and some suitable combustible liquid or gaseous fuel are introduced, mixed, and ignited, the gaseous products of combustion escaping rearwardly through an exhaust nozzle at high velocity.

It is also my object to provide means for diverting a portion of the water which normally surrounds the torpedo into the stream of exhaust gases in order to increase the mass of fluid which is given. a backwardacceleration with respect to the torpedo and-thereby increase the forward thrust on it.

Other objects and advantages will become more readily apparent upon consideration of the appended drawing and the following detailed description which is to be considered in connection with it. l

Referring now to the drawing, a schematic diagram of the stern of a torpedo embodying my improved propulsion means is shown.

In the drawing, the casing l is formed in such a maner as to contain a combustion chamber 2 which has, for the purpose of maximum heat dissipation, a substantial proportion of its walls in direct contact with the water which normally completely surrounds the torpedo casing. The combustion chamber 2 is provided with a pair of orifices or nozzles 3 and 4 for admitting a pair of fuel constituents such as gasoline and air or oxygen respectively into the combustion chamber. In some cases. it may be desirable to provide more than two such fuel inlet ports so that three or more fuel constituents may be mixed and burned in the combustion chamber. It is preferable butnot absolutely essential that their axes intersect for best mixing of the fuel and air or oxygen. The size of the restricting orifices 3 and i with respect to one another determines the proportion. of fuel-air mixture which may be admitted into :the combustion chamber 2. It will usually vbe preferable to x the orifice sizes at some predetermined ratio without any necessity for further adjustment, as is shown in the drawing; howeveiyif for any' reason it may be desired to vary the fuel-air mixture at will, a throttle valve or the like may be used in connection with the orifice 3 or t or both.

In operation, the torpedo will be discharged from a tube by compressed air in the usual manner. This will cause a starting lever (not shown) to be tripped, which will in turn open the pressure regulating valve I3, thereby allowing air or oxygen to flow from the pressure storage tank Il,

through the conduit l2, the pressure regulating valve I3, the conduit I4, the uid pressure motor IG, and the conduit Il to the orice or nozzle d.

'The fluid pressure motor or pneumatic type motor I6 is preferably of the rotary type which is 'actuated by the passage of fluid through it, in this case the passage of air or oiwgen from conduit I6 to conduit l1. Operation of the air motor rotates' the spindles or shafts I8 and I9 which bring about simultaneous operation of the gyroscope 2| and the fuel pump 8. The gyroscope 2l is operably connected to the rudders 2l) and elevators (not shown) in the usual manner whereby the torpedo is maintained on its course when in operation. Operation of the fuel pump 8 will cause fuel to flow from the tank 6, through the conduit l, the pump 8, and the conduit 9 to the lture isbeing burned to propel the torpedo ,through the water. A

Any preferred means for igniting the fuel-air mixture may be employed such, for instance, as the one which I have shown consisting of a storage battery 22, a coil 23 and an igniter 24 in which are mounted the spark -electrodes 26 and 21.

An exhaust outlet nozzle 28, preferably of a rearwardly extended tubular shape, is provided for the discharge of gases under pressure from the combustion chamber 2. Since the forward thrust which will be achieved by this type of propulsion is to a great extent dependent upon the total mass of fluid which can be accelerated rearwardly with respect to the torpedo, the -highest -efiiciency may be realized by diverting an amount of water which is relatively heavier than the combustion products across the outlet Anozzle 28 and into the stream 31 of escaping combustion products. For this purpose I have provided a shell 29 surrounding the rear of the casing I and spaced apart therefrom a suiiicient distance to provide channels 3l which serve to direct the ow of water across the outlet nozzle 28 as indicated by the arrows 32. Thus, it will be seen that the flow of combustion products 3l' through the tubular extension 33 of the shell 29 createsa low pressure area in the portion 34 of the channels 3l, resulting in a pressure differential between the channel portions 34 and the surrounding waterl 36 thus causing water to be aspirated into the stream of combustion products 31.

It should be apparent that by the use of a reaction type propulsion means such as I have disclosed, a torpedo so powered may attain speeds substantially higher than are possible in conventional torpedoes motivated by the usual propeller drive; for, to increase speed in my propulsion means it is necessary only to increase the rate of combustion, which obviously may be done without changing the dimensions of the torpedo from present standards. Thus the inherent disadvantages of the conventional propeller drive which prevent the achievement of higher speeds without increasing the size of the torpedo are obviated and at the same time a simpler propulsion device is utilized; in this latter connection it is pointed out that my propulsion means utilizes a great many less moving parts than are employed in the conventional propeller drive type of torpedo. l,

While I have shown and described one form of my invention I desire that it be regarded merely as illustrative. There will obviously be many other modications within the scope of the appended claims. For instance, in some cases it may be desirable to burn gaseous fuel instead of liquid fuel, in which case the fuel pump 8 may be dispensed with, since the fuel would then be supplied in gaseous form from a high pressure tank in the same manner as I have shown the air'or oxygen being supplied.

I claim: l 1.. Propulsion means for a naval torpedo comprising a casing formedto contain a combustion chamber suitable for the mixture and burning of combustible fluids, a plurality ofconduits for supplying said combustion chamber with a plurality of combustible fluids in a predetermined proportion, one of said conduits having fluid operable motor means therein, another of said conduits having pump means therein associated with said motor means wherebv flow of fluids is necessarily simultaneous through the motor and pump-containing conduits, means for discharging the products of said combustion in a stream rearwardly of said torpedo, aspirator means associated with said stream of discharging combustion products adapted to divert a portion of the water medium immediately surrounding said torpedo into said stream of discharged combustion products.

2. Propulsion means for a naval torpedo com,

prising in combination, a casing formed to include a combustion chamber at the stern thereof, said casing having a first inlet and a second inlet for thev admission of fuel and oxygen re spectively into said combustion chamber, said first inlet being supplied with fluid fuel by pump means, said second inlet being supplied with oxygen from a constant-pressure source through a conduit con-taining motor means, said motor means being operable by flow of oxygen from said constantpressure source to said second inlet, said motor being in operative relation with said pump means, said casing having a stern opening in communication with said combustion chamber for discharging a 'rearwardly directed stream of combustion products. means associated with said stern opening for directing a portion of the water medium normally surrounding said casing into said stream of combustion products, said casing being so constructed that a substantial proportion of the walls of said combustion chamber is in direct contact with said water medium.

3. Propulsion means for a naval torpedo comprising a casing having a combustion chamber therewithin, said casing having ports for the admission of combustible fluids to said combustion chamber, at least one of said fluids being a freely expansible gas, a conduit adapted to convey said expansible gas from a pressure reservoir, through pressure regulating means anda pneumatic-type driving means to said expansible fluid port in said casing; the other of said fluid ports in said casing wall being connected to a fluid reservoir by means of a conduit having a pump therein; said pump being driven by said pneumatic-type-driving means whereby the speed of said pump is proportional to the speed of said driving means, whereby further the quantity of uid passing through the pump is directly proportional to the quantity of fluid passing through said driving means; lignition means within said combustion chamber for initiating combustion; said casing having an exhaust port for said combustion chamber so positioned that the products of combustion are discharged through said exhaust port and rearwardly of said torpedo.

DONALD G. FAWKEs. 

